Mij
Senior Member (Voting Rights)
Abstract
Genetically encoded indicators that can detect concentrations of metabolites and signalling molecules through fluorescence lifetime changes are gaining attention, because they expand the potential for quantitative imaging. These indicators offer advantages over conventional fluorescence intensity-based indicators by minimizing artifacts such as variations in indicator concentration, cellular morphological changes, and focus drift. However, the availability of fluorescence lifetime-based genetically encoded indicators remains limited, particularly those compatible with the widely used conventional 488 nm laser in microscopy.
Here, we introduce qMaLioffG, a single green fluorescent protein-based ATP indicator that exhibits a substantial fluorescence lifetime shift (1.1 ns) within physiologically relevant ATP concentrations. This enables quantitative imaging of ATP levels in the cytoplasm and mitochondria under steady-state conditions across various cell types, providing insights into ATP distribution. We demonstrate that qMaLioffG can be used in multicellular systems, applying it to Drosophila brain and HeLa cell spheroids to reveal spatially heterogeneous ATP levels.
STUDY
Scientists develop a new method to measure cellular energy in real time
Key Findings
Potential Impact
This new method is expected to accelerate research in energy metabolism, regenerative medicine, and disease mechanisms. Because it works with standard 488 nm laser systems already common in many labs, it will be widely accessible to researchers worldwide.
Future Research
Although qMaLioffG represents a significant leap forward, several challenges remain. The current study focused on cultured cells, model organisms, and tissue-like spheroids; applying the method to whole living organisms and ultimately human tissues will be the next step. Researchers also need to explore how qMaLioffG performs in long-term imaging, since energy metabolism is highly dynamic and can fluctuate over hours or days.
Future directions include:
Genetically encoded indicators that can detect concentrations of metabolites and signalling molecules through fluorescence lifetime changes are gaining attention, because they expand the potential for quantitative imaging. These indicators offer advantages over conventional fluorescence intensity-based indicators by minimizing artifacts such as variations in indicator concentration, cellular morphological changes, and focus drift. However, the availability of fluorescence lifetime-based genetically encoded indicators remains limited, particularly those compatible with the widely used conventional 488 nm laser in microscopy.
Here, we introduce qMaLioffG, a single green fluorescent protein-based ATP indicator that exhibits a substantial fluorescence lifetime shift (1.1 ns) within physiologically relevant ATP concentrations. This enables quantitative imaging of ATP levels in the cytoplasm and mitochondria under steady-state conditions across various cell types, providing insights into ATP distribution. We demonstrate that qMaLioffG can be used in multicellular systems, applying it to Drosophila brain and HeLa cell spheroids to reveal spatially heterogeneous ATP levels.
STUDY
Scientists develop a new method to measure cellular energy in real time
Key Findings
- qMaLioffG provides reliable, quantitative imaging of ATP in living cells.
- The method works in diverse systems, from patient-derived fibroblasts to cancer cells, stem cells, and fruit fly brains.
- It reveals subtle differences in energy use across different tissues and disease models.
Potential Impact
This new method is expected to accelerate research in energy metabolism, regenerative medicine, and disease mechanisms. Because it works with standard 488 nm laser systems already common in many labs, it will be widely accessible to researchers worldwide.
Future Research
Although qMaLioffG represents a significant leap forward, several challenges remain. The current study focused on cultured cells, model organisms, and tissue-like spheroids; applying the method to whole living organisms and ultimately human tissues will be the next step. Researchers also need to explore how qMaLioffG performs in long-term imaging, since energy metabolism is highly dynamic and can fluctuate over hours or days.
Future directions include:
- Clinical validation, adapting qMaLioffG for use in patient-derived samples to study diseases such as cancer, diabetes, and neurodegeneration.
- Integration with other imaging methods, combining ATP mapping with calcium or pH sensors to understand how energy connects with cell signaling.
- Drug discovery applications, using the method to test how new compounds affect cellular energy balance.